Animal models: Usefulness for studies of fungal pathogenesis and drug efficacy in aspergillosis

This review describes our experience during the past 8 years with an immunocompromised rabbit model of invasive aspergillosis. We have used the model to evaluate the efficacy of a variety of antifungal therapies, including amphotericin B-deoxycholate, a liposomal amphotericin B preparation, some of the newer azoles (i.e., fluconazole, saperconazole, and the experimental compound SCH 39304), and combination therapy with amphotericin B-deoxycholate plus fluconazole. The model provides a rigorous test of efficacy when animals receive a lethal challenge; permits studies of the kinetics of aspergillar antigenemia in response to therapy with each antifungal agent or regimen; allows comparison of the relation of antigenemia to the extent of disease in target organs; and is useful in correlating the timing of antifungal therapy with the success of treatment. These observations in our animal model may provide some insight into the treatment of invasive aspergillosis in humans.